Sealing

ABSTRACT

The invention concerns a method for sealing a surface ( 13 ) of a body ( 11 ), wherein a thin material ( 21 ) is applied to the surface ( 13 ) and is connected to it by means of melting due to mechanical stimulation.

[0001] The invention concerns a sealing method according to the claims.

[0002] There are various known methods for sealing surfaces. These arebased on the application of a protecting layer by means of varnishing orby gluing. The disadvantage of these methods is that in particular edgesand corners of chipboard, parquet floors or wood fiber boards cannot besealed sufficiently. Thus e.g. on a correspondingly treated parquetfloor the problem arises that moisture penetrates especially through thelateral surfaces of the boards which causes moisture expansion of thematerial. In addition these methods are complicated, costly andinflexible and they require complex apparatuses.

[0003] The object of the invention is to create a method which avoidsthe named problems.

[0004] The sealing method according to the invention is based onapplying a thin material to the surface to be sealed and on connectingthe material to this surface by temporary melting using heat beingcaused by mechanical stimulation (by means of a piezo-element). The thinmaterial is e.g. a film (or foil) material or a strip. The thin materialis connected adhesively to the body to be sealed or to its surfacerespectively by means of partial, temporary melting, such that apermanent sealing is achieved, which guarantees a sufficient sealingagainst moisture and other environmental influences. The temporarymelting is advantageously carried out without a thermal heat source, bymeans of heat caused by friction due to mechanical stimulation,advantageously by vibrations. The frequency of the vibrations istypically located at the upper end of the audible region or in theultrasonic region. With heat caused by friction the material can bemelted in a controlled way. By application of pressure the filling ofpores and cavities in the surface to be sealed is achieved. Due to thelarge shearing effect the melted material has a very low viscosity, suchthat even capillary cavities are filled. The depth of penetration of aspecific material can be adjusted, among others, by adjusting frequencyand amplitude or duration of the application of the vibration. Themethod is applicable to practically all surfaces of a body. With asuitable arrangement it is possible to seal large surfaces continuouslyor in sections. The method can be applied in stationary or in flexiblemanner. By means of suitable devices it is e.g. possible to seal largesurfaces (e.g. floors of gymnasiums, any type of lining, etc.). Thematerial used for sealing can, if required be provided with decorativeelements such as patterns or images. It is e.g. possible to seal acarrier with a film with color print, such that the impression of a realparquet floor is created. A decorative layer can also be processedseparately. It is not a condition that all areas are sealed. In certaincases it is sufficient for critical areas only to be treated with themethod described here.

[0005] The method is advantageously used for sealing surfaces of porous,fibrous materials such as wood, chipboard, cork, cardboard, fiberboardand also concrete, clay, etc. The invention is characterized, amongother things, in that it is applicable for continuous processing.Because no solvents are required the method does away with lengthyperiods of and complicated apparatuses for drying. The invention baseson the short and locally restricted melting of an advantageouslythermoplastic material. It is advantageous that, due to the very shortmelting and cooling periods, no significant waiting periods arise.Furthermore, due to the short processing time, the melted material isprocessed in an extremely sparing manner.

[0006] The characteristics of the surfaces can be adjusted by means ofapplying several films. It is e.g. possible to combine a first layerwith decorative patterns with a further layer which is particularlyresistant against abrasion. This multi-layer technology can be appliedin one or several process steps. As the used materials are usually suchthat they can be melted thermally it is possible to apply several layersat intervals. Functional edges (plug or snap connections) can be sealedpermanently.

[0007] Surfaces treated according to the invention can also be connectedtogether by renewed, mechanical stimulation resulting in an effect withfurther depth. Thus it is e.g. possible to stimulate flooring whichconsists of a plurality of individual parts (slabs, tiles, boards) withedges being in mutual contact with each other, such that these edges arepermanently bound to each other. In addition or as an alternative othermeans for connecting such edges, adhesives can also be used.

[0008] The invention is described in detail in connection with thefollowing figures. It is evident that the invention is not restricted tothe shown embodiments.

[0009]FIG. 1 shows a diagrammatic overview of the inventive method;

[0010]FIG. 2 shows a detail of FIG. 1;

[0011]FIG. 3 shows the application of the method to a groove.

[0012]FIG. 1 shows, in diagrammatic manner, the main steps of the methodaccording to the invention. Panels 10, 11, 12 are shown, the top sides13 or the narrow sides respectively of which are sealed. Panels 10, 11,12 are guided past a processing device 1 by conveying means 2 in thedirection of arrow P. The conveying means 2 consist of a plurality ofconveying rollers 3 and 4 being rotateable around their axes and beingin interaction with the panels 10, 11, 12 in such a manner that theysupport these and guide them past the conveying device 1. The conveyingmeans 2 are mounted on supports which for clarity reasons are not shownin detail and they are driven by a corresponding drive (not shown indetail), e.g. a chain drive, an electric motor or a hydraulic drive.

[0013]FIG. 2 shows (detail of FIG. 1) the processing device 1, a panel11 being processed and conveying rollers 3 and 4. A storage reel 20,onto which a tape 21 is wound serves as storage. The tape 21 is unwoundover a first and a second guiding roller 22, 23 and is positioned on thesurface to be sealed. The second guiding roller 23 presses the tape 21onto the surface 13 of the panel 11 with a specified force F1. Themovement of guiding rollers 22, 23 and storage reel 20 are matched toeach other in a manner that the tape 21 is transferred to the surface 13to be sealed and, if so required, is subject to a predetermined tension.The storage reel 20 and guiding rollers 22, 23 are mounted rotateablearound axes 27, 28, 29. The processing device 1 is mounted in stationarymanner and the panel 11 moves in relation to it in the direction ofarrow P and guided by guide means 3, 4. After passing below roller 23,the panel 11 passes a sonic head 24 which is functionally coupled withthe panel 11 and the tape 21. The tape 21 is connected with the surface13 through temporary melting. The melting is advantageously carried outvia mechanical stimulation such that the tape 21 and/or the surface 13is melted partially due to friction heat. By means of pressure, showndiagrammatically by an arrow F2, the melted materials are additionallyconnected. The sonic head 24 is designed such that it corresponds to thesurface to be processed, such that this surface, especially in theregion around the edges 30, 31, is sealed effectively. The sonic head24, in this embodiment protrudes over edges 30, 31 of panel 11. Thus itis also possible to process tapes 21 which are wider than the thicknessof the panel 11, such that the sealing reaches beyond the area 13. Anoverlap of several layers is possible. If required, sonic heads withother characteristics can be used. The resonator 24 is brought intovibration by an actuator 25. The stimulating vibrations areadvantageously generated by means of a piezo-element (not shown indetail) coupled to sonic head 24 (sonotrode). Depending on the field ofapplication other sorts of mechanical stimulation can be used. At theend of panel 11 a trimming device 26 cuts tape 21 off. The trimmingdevice 26 is advantageously designed such that it positions the tape 21for processing the next panel 12 (see FIG. 1).

[0014]FIG. 3 shows, in a very simplified manner, how a profiled groove35 of a panel 11 is sealed. The groove 35 is part of a snap or plugconnection for connecting the panel 11 to further panels or other bodies(not shown in details being formed accordingly. Processing of thiscounterpart is carried out in analogy to the method described here andtherefore is not explained in detail.

[0015] A tape 21 is pressed against a surface 35 of a panel 11 by meansof a sonic head 24. Due to the friction heat generated by vibration ofsonic head 24 the advantageously thermoplastic tape 21 (or an equivalentmaterial with a corresponding coating) is temporarily melted and pressedinto the surface 36. This process is indicated diagrammatically byarrows 37. The sonic head 24 is pressed against surface 36 of groove 35,such furthering penetration of the melted material into the surface.Beforehand, the tape 21 is brought into groove 35 in a continuous mannerand, if necessary, is fixed by suitable means, in order to preventunwanted shifting. The (relative) movement between panel 11 and sonichead 24 during processing is shown by an arrow 38. The sonic head 24 isentered into groove 35 at its beginning. Further sonic heads are usedfor sealing other surfaces (not shown in detail). The sonic head 24 hasa shape which is adapted to the surface to be sealed. It isadvantageously designed such that a plurality of surfaces can beprocessed simultaneously. Undercuts can also be treated with suitablydesigned sonic heads. The sealing of the surface is carried outcontinuously or in sections. The other surfaces are processed withaccordingly shaped sonic heads (not shown in detail). The design of thesonic heads determines the pressure exerted on the surface. A sonic headcan comprise several parts, movable relative to each other, such that itadapts to the outline. Snap- or plug-connections between parts can bemade permanent and tight by renewed melting of the sealing material.

[0016] The specialist may, with knowledge of the present invention,apply it to other bodies and their surfaces.

1. Method for sealing a surface (13) of a body (11), characterized inthat a thin material (21) is positioned on the surface (13) and thatthis thin material (13) is connected to the surface by means of melting,due to mechanical stimulation via a sonic head (24).
 2. Method accordingto claim 1, characterized in that the mechanical stimulation isgenerated by means of a piezo-element.
 3. Method according to one of thepreceding claims, characterized in that the thin material (21) is a filmor a tape.
 4. Method according to one of the preceding claims,characterized in that the thin material (21) and/or the surface (13) ismelted partially.
 5. Method according to one of the preceding claims,characterized in that the melting is carried out under pressure (F2). 6.Method according to one of the preceding claims, characterized in thatseveral thin materials (21) are applied.
 7. Method according to one ofthe preceding claims, characterized in that one of the thin materials(21) comprises decorative elements.
 8. Use of the method according toclaim 1 for sealing surfaces of wood, cardboard or metal, for flooringand wall lining.
 9. Device (1) for sealing a surface (13, 36) of a body(10, 11, 12) with a thin material (21), characterized by a storage (20)from which the thin material (21) is taken, a positioning means (22, 23)for positioning the thin material (21) on the surface (13, 36) to besealed, and a sonic head (24) for connecting the thin material (21) withthe surface (13, 36) by melting the thin material (21) and/or thesurface (13, 36) through mechanical stimulation.
 10. Device according toclaim 9, characterized in that a piezo-element serves the mechanicalstimulation of the sonic head.